This project is concerned with the isolation, identification, and pharmacological evaluation of new anticancer agents from marine organisms, in particular from marine cyanobacteria. Studies will be carried out to isolate and identify water-soluble and lipophilic substances from several Lyngbya species and other cyanophytes that show activity against P-388 lymphocytic mouse leukemia. In most cases the active substances will be isolated from field collections of the organisms, but in some cases cultured materials will be required.